4c+3c-2c(c=4)

Solution for 4c+3c-2c(c=4) equation:

4c+3c-2c(c=4)

We move all terms to the left:

4c+3c-2c(c-(4))=0

We add all the numbers together, and all the variables

7c-2c(c-4)=0

We multiply parentheses

-2c^2+7c+8c=0

We add all the numbers together, and all the variables

-2c^2+15c=0

a = -2; b = 15; c = 0;
Δ = b2-4ac
Δ = 152-4·(-2)·0
Δ = 225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{225}=15$
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(15)-15}{2*-2}=\frac{-30}{-4}
=7+1/2
$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(15)+15}{2*-2}=\frac{0}{-4}
=0
$